Extractor column having alpha liquid level regulator



Feb. 16, 1932. J, M, COAHRAN 1,845,129

EXTRACTOR COLUMN HAVING A LIQUID LEVEL REGULATOR Filed July 12. 1927 2Sheets-Sheet l eee gvnl/111111111111111111, l

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EXTRACTOR COLUMN HAVING A LIQUID LEVEL REGULATOR Filed July 12, 19272`shee1s-Sheet 2 Patented Feb. 16, 1932 l UNET STATES- PATENT OFFICEJESSE M. COAHRAN, F SlVIETHPORT; PENNSYLVANIA Ex'rRAo'roR COLUMN HAVING.

Applicationiuea Juiy 12,

In my application for Patent Serial No.

3,797 filed January 21, 1925, for apparatus for extracting chemicalsfrom liquors is shown and described a countercurrent flow A apparatus inwhich a relatively heavy liquor containing chemicals which itis desiredto extract therefrom is caused to dow downwardly through a column, whilea relatively light fluid solvent for the chemicals is caused to pass upthrough the column in intimate contact with the descending liquor. Incarrying out the process for which this apparatus was designed, it isimportant to maintain a pool of substantially fresh solvent in the lowerpart of the column, through which pool the nearly extracted Aliquor iowsin diffused condition before it is withdrawn. In order, however, that nosolvent shall be withdrawn with the extracted or exhausted liquor, itis. necessary to maintain the extracted liquor.

in a pool beneath and supporting the pool of solvent, the plane ofdemarcation between* the extracted liquor and the solvent beingmaintained at a point substantially, abovel fthe spent liquor outlet.When aceticacid is being extracted rfrom pyroligneous acid liquor by asolvent such as ether, the plane of demarcation between the extractedliquor and the solvent pools may be seen by the use fof a sight glasscommunicating with the interior of the column above and below thisplane, and the level of this plane may be kept within reasonable limitsof that desired by careful and frequent manipulation of the spent liquoroutlet valve. ln other cases,

however, it might be dicult to determine g eral eficiency of thecontinuous process.

The present invention, therefore, has for its object to provide a devicewhich will main- Y tain this plane between the two liquidsclose ALIQUIDLEVEL REGULATOR 1927. serial No. 205,111. i

to the desired level automatically and 'with-v out regard as to whetheror notit is readily determinable by sight. K. To this .ei'id a fioatweightedto maintain a constant level relative kto this plane andVsubjected to the buoyant action of the liquid in the column is arrangedto Acontrol the spent liquor outlet valve so as to shut the valve astheV plane descends and to open the, valve as the plane rises. By asuitable proportioning of the parts, therefore, this plane may bemaintained substantially at a constant level.V y

For a more complete understanding of this invention, reference may behad to the ac-V companying drawings in which Figure 1 is a fragmentaryvertical section through the columnk showing the level control deviceapplied thereto. Figure 2 is a fragmentary section ofthe column showingportions not disclosed in l.mA

Figure 1. f y

Figures 3 and f1 aredetail sections on lines 3 3 and 4 4, respectively,of Figure 2.

Referring to these figures, 1 indicates a column having near its upperend a heavy liquid inlet 2 and above this a lightliquid outlet 3.f Nearthe lower end of the column is a light liquid'inlet 4 and below this isa heavy liquid outlet 5. The heavy liquid inlets and outlets are forvthe passage of the liquor from which the chemicals are to be extractedandthe light liquid inlet and outlet for the relatively light, solvent.Extending axially through the column i'sshown a shaft 10 hav# ing fixedthereto between the heavy liquor inlet and the light liquor inlet,'threesets of ystirring or agitator members indicated, respectively, at 11, 12and 13. Alternately arranged with each of the agitators 12 the series ofwhich extend the greater part of the length of the column are fixedbaille plates 15 extending inwardly froin the wall of the column, each'having a central opening 16 through which the shaft l0 passes, thisopening being somewhatlarger ythan the shaft so as to permit therestricted passage'of the light liquid upwardly and the heavy liquiddownwa'rdly about the shaft. Each of the agitators 12 is formed as aflat disk having a plurality of ribs 20 radially arranged thereon andco-` 100 operating with similarly radially arranged ribs 21 on thestationary baffles 15. There are no stationary bales adjacent to andbetween the stirrers ll and 13 and as shown in Figure 4 these stirrersl1 and 13 are formed with alternate open and solid portions 25 and 26,the open portions of one stirrer being arranged in vertical alinementwith the closed portions 26 of the adjacent stirrer. The central seriesof agitators 12 is intended to thor-A oughly miX the descending heavyliquor and the ascending light solvent at the internisdiate portion ofthe length of the column, while the stirrers 1l are intended to diffusethe ascending solvent liquor through a pool of substantially fresh heavyliquid at the upper portion of the column, and the stirrers 13 areintended inlilre manner to diffuse the descending nearly extracted heavyliquor through a relatively large pool of substantially fresh solventmaintained in the lower portionv of the column. After passing throughthis pool of substantially fresh solvent, the solvent being suppliedthereto through the inlet 4, the heavy spent liquor is allowed tocollect in the bottom of the column Y and is drawn oiic through theoutlet 5.

The extreme upper and lower portions of the column are free fromagitators of any description so as to permit the heavy and light liquidsto separate by gravity so that the light liquid may be drawn off withits chemical content .removed from the heavy liquor through the outlet3'without being contaminated by the heavy liquor entering through theinlet 2 and so that the heavy spent liquor may be drawn out through theoutlet 5 without carrying therewith solvent introduced through the inlet4. Thejshaft 10 may be rotated in any suitable manner, as by means ofthe pulley 30 at its upper end. This portion of the apparatus may be thesame as that disclosed in my application hereinbefore re-` ferred to.

The plane of demarcation between the spent heavy liquor and the pool ofsubstantially. fresh solvent superposed thereonv should be slightlybelow the inlet for the solvent at 4 Vor aboutat the line a-a of Figurel. Tn ord-er to maintain the level at this point, a controlling devicehas been devised. This device comprises a casing 35, the lower end ofwhich communicates withvthe lower end of the column as through the heavyliquor outlet 5, and the upper portion of which communicates through thepipe 36 with the col-- umn just beneath the lowest stationary baffle(see Figure 2). The lower end of the casing 35 is closed oif by means ofa valve plate 37 having a central opening 38 therethrough surmounted byan annular valve seat 39 sul stantially concentric to the opening 38 butof an internal diameter somewhat larger than this opening. On the lowerside of the valve plate 37 is theheavy liquid outlet 40'. Slid! ablethrough the opening 38 of the valve plate is the valve member 4l. Thiscomprises a tubel provided with a considerable number of radiallyextending openings 42 through its wall, and surmounted by an imperforatecap plate 43 which when the valve is in its lowest position rests on'theupper face of the valve seat member 39 and completely closes the outlet40. As the valve is raised,cmore and more of the perforations 42 arebrought above the valve plate 37 so as to permit ainincreasing quantityof the heavy liquid to escape therethrough into the valve tube and passout through the outlet 40. By placing the openings 42 radially the valveis substantially balanced in so far as any eect of the iiow of liquidtherethrough is concerned, at least until such time as the disk 43 isvery near to its closed position. This Valve is connected by means of arod 44 at its lower end adjustably threaded into the disk 43 and havinga loop 45 at its upper end to a depending portion 46 of a float 47. Thisfloat is preferably formed hollow and is providedl with guiding lugs 48to guide it for vertical movement within the casing 35, while permittingthe passage of liquid therepast. At its upper end it is provided with afilling opening at 50 which may be closed by a suitable plug so that anysuitable weighting material, such as a liquid or granular material, maybe poured into its interior until the weight of the float is such as tocause it and the valve to tend to assume a position with substantiallythe lower half of the float immersed in the heavy liquid and the upperhalf immersed in thelight solvent. When weighted in this manner, if theplane of demarcation between the liquid descends, the

float and the valve descend therewith, closing the valve somewhat so asto diminish the escape of spent liquor, while if the level of the planeof demarcation rises the float also rises, opening the valve wider andpermitting a more rapid escape'of the spent liquor. The upper end of thecasing 35 is shown as closed off by a cover member 55 through which isthreaded an abutment rod 56 which should be so adjusted that the floatcontacts therewith, so that its upward movement is stopped before thelower end of the valve tube is raised clear of the valve plate 37.

This device, it will be seen, act-s to regulate the level of the planeof demarcation between theV heavy and light liquids within relativelyclose limits and in actual operation effects a substantially steady iowof spent liquor, thus adding to the general etiiciency of the conly bythe proportions of the two liquids and the speed of the rotor. Thesefactors once adjusted, the upper level seems to take care of itself,consequently no regulator for this upper level has been shown herein.

Having thus described an embodiment of this invention, it should beevident to those skilled in the art that various changes andmodiiications might be made therein without departing Jfrom its spiritor scope as deiined by the appended claims. Y

I claim:

l. The combination with a column having a heavy liquid inlet adjacent toits top, a light liquid inlet adjacent to its bottom, a light liquidoutlet above the heavy liquid inlet, a heavy liquid outlet below thelight liq- ,i

uid inlet, and means between said liquid inliquid inlet and an outlet atthejupper portion of said column, a liquid inlet and an outnature. n

JESSE M. COAHRAN.

lets for producing intimate contact between liquids between said lightliquid inlet and said heavy liquid outlet.

2. In combination with a column having a Y heavy liquid inlet adjacentto its top, a light liquid inlet adjacent to its bottom, a light liquidoutlet above the heavy liquid inlet and a heavy liquid outlet below saidlight liquid inlet, means between said light and heavy liquid inlets formixing the liquids while permitting them to separate out by gravity atthe end portions of said column into distinct layers, a chamber incommunication with said column above and below said light liquid injlet, a float in said chamber weighted to float partly submerged in eachliquid and substantially at the level therebetween in said column, andmeans controlled by said lloat to maintain said level substantiallyconstant between said heavy liquid outlet and said light liquid inlet.

3. In combination, a column having separate liquid inlets and outletsadjacent to its upper and lower ends, agitating means between said upperand lower inlets and outlets, the upper and lower portions of saidcolumn between the inlets and outlets of said portions being free fromagitating means to permit liquids of diii'erent specific gravities insaid column to separate out by gravity into distinct layers, and meanscontrolled by the level between said liquids at the lower end of saidcolumn Jfor controlling the escape of liquid through said lower outletto maintain said level substantially constant between said lower inletand outlet.

4. An extractor, comprising a column, a

